Preequilibrium emission of nucleons and coalescence of complex particles in heavy-ion reactions

The emission of protons and light complex particles from a variety of heavy-ion collisions at 15-25 MeV/nucleon has been studied. The proton data have been analyzed using a refined multisource analysis in which a new expression taking explicitly into account the anisotropy of preequilibrium particles in the c.m. system has applied. Proton yields from central-like collisions have been compared with a Boltzmann master-equation calculation; the comparison has shown that the excitation energy per initial degree of freedom is essentially independent of the projectile and target masses and depends only on the per nucleon energy brought in by the projectile. The complex-particle data are compared with the coalescence model; the extracted coalescence radii show a stricking dependence on AP/(AP + AT) for both strongly bound α particles and weakly bound deuterons